can Graphics handle a 4 by 4 of 8x8 neopixel board

All I can suggest is that you access the underlying array with g.buffer and re-order the pixels yourself before sending them.

// g = Graphics
leds = new Uint8Array(16*16*3);

g.flip = function() {
  leds.set(new Uint8Array(g.buffer,0,8*3), 0);
  leds.set(new Uint8Array(g.buffer,8*3,8*3), 8*8*3);
  leds.set(new Uint8Array(g.buffer,2*8*3,8*3), 8*3);
  // etc ...
  SPI1.send4bit(leds,...);
}